Heretofore digitizing arrays have employed external collimating optics for focusing an array of light beams propagating from a send waveguide array to a receive array. The collimating optics were typically an array of collimating lenses which was secured to the send array during assembly. The collimating array was not an integral part of the waveguide array, and did not have a precisely defined position relative to the waveguides. During assembly, the optics were manually (or mechanically) placed next to the waveguides for securing. Precise optical alignment under such unrestrained conditions was difficult resulting in misalignment. This assembly misalignment introduced a corresponding indexing error between the waveguides and the optics which degraded the collimation causing limited the position resolution of the light beams. However, the prior art light beam density was sufficient for selecting icon symbols from a displayed menu.